NExt-Generation Sequencing and Cell Culture-based Characterization of S. Aureus in Infective Endocarditis

Infective Endocarditis Clinical Trial

— NESSIE  

Official title:

NExt-Generation Sequencing and Cell Culture-based Characterization of S. Aureus in Infective Endocarditis

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT04257292
• Other study ID #: 01
• Status: Recruiting
• Start date: September 1, 2019
• Est. completion date: July 31, 2020

Study information

• Verified date: February 2020
• Source: Jena University Hospital
• Contact: Mahmoud A Diab, Dr. med.
• Phone: 03641
• Email: mahmoud.diab[@]med.uni-jena.de
• Is FDA regulated: No
• Study type: Observational

Clinical Trial Summary

Infective endocarditis is a deadly disease with a mortality rate between 20 and 40%. Antibiotic therapy is of utmost importance. It is primarily guided by microbial results from positive blood culture. However, culture-based microbiological diagnostic can identify the species, but not the strain or the genotypic characteristics of a pathogen. Identifying the strain can be of utmost clinical significance. S. aureus is the most common causative organism of IE worldwide (16%-32%). This pathogen causes massive valve destruction and abscesses, which is strongly dependent on the expression of virulence factors that vary between different S. aureus strains.

Functional characterization of S. aureus and determination of virulence factors can currently be achieved through cell culture-based assays (CCBA). However, these tests are very time consuming and cannot be performed as routine clinical diagnostics. Next Generation Sequencing (NSG) has the potential to identify the genotypic characteristics of the pathogen, which is important to determine its virulent potential.

The aim of this study is to evaluate the possible utilization of NGS in the prediction of virulence factors of S. aureus and to compare it to the virulence factors determined using CCBA.

Hopefully, by comparing the NGS and CCBA, the investigators will get a faster way of determining the possible virulence factors. The NGS method can be further utilized to describe the prevalence of different strains of bacteria in infected valve tissue and blood culture samples. The collected data will serve as a basis for further evaluation of the potentials of NGS-based Diagnosis of IE, as well as a comparison between NGS-guided antibiotic treatment and the standard of care antibiotic treatment.

Description:

The ability of the Staphylococcus aureus to produce massive valve destruction as well as abscesses and to switch from acute to chronic infection and vice versa is a significant issue in the modern treatment of infective endocarditis. Furthermore, the ability to produce different virulence factors to evade the immune defense mechanisms proves the treatment more difficult. Another conundrum is the proof of different S. aureus strains isolated from Blood culture samples and infected valve samples. This makes a possible treatment of S. aureus-based endocarditis more difficult than expected.

Isolation of Bacteria in the Blood culture samples can take much time (3-14 days), and Cell Culture-based assays (CCBA) are not regularly implemented as a diagnostic procedure. CCBA is not regularly used in the clinical setting due to the time consumption and high cost. The significance of the CCBA method lies in the determination of the possible virulence factors. Utilizing the Next Generation Sequence (NGS) method, it might be possible to gain this information about the culprit microorganism faster and to identify the different strains and virulence factors.

To date, such correlations between genetic information about virulence factors gained by NGS and phenotypic information obtained by cell culture-based assays have not yet been performed.If proven, the NGE based analysis of the pathogens and their phenotypical behavior could guide antimicrobial therapy and make it individualized. Blood culture and infected tissue valve samples will be examined using the NGS and CCBA. The investigators aim to compare the differences in virulence factor results in these two methods, to characterize the prevalence of different strains of S. aureus in the blood culture and valve samples and to evaluate the possible potentials of NGS-based diagnosis of IE and to compare the effects of the NGS-guided antimicrobial therapy to the standard of care therapy.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 10
• Est. completion date: July 31, 2020
• Est. primary completion date: February 28, 2020
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• patients with the diagnosis infective endocarditis and indication for heart surgery on a heart valve

• signed informed consent

• age =18 years

• pathogens (S. aureus) can be isolated from blood culture AND from the removed valve tissue

Exclusion Criteria:

• S. aureus can not be isolated from removed valve tissue

Related Conditions & MeSH terms

• Endocarditis
• Endocarditis, Bacterial
• Infection Staphylococcal
• Infective Endocarditis
• Staphylococcal Infections

Locations

Country	Name	City	State
Germany	Jena University Hospital, Clinic for Cardiothoracic surgery	Jena

Sponsors (2)

Lead Sponsor	Collaborator
Jena University Hospital	Fraunhofer Institute for Cell Therapy and Immunology, Leipzig, Germany

Country where clinical trial is conducted

Germany, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	biofilm growth	ability of S. aureus strains isolated from the blood and heart tissue of included patients to build a biofilm	through study completion (about 1 year)
Secondary	invasion characteristics	characteristics of the S. aureus strains isolated from the blood and heart tissue of included patients to invade other cells (host cell invasion; persistence in host cells; tests will be conducted in cell culture)	through study completion (about 1 year)
Secondary	adhesion characteristics	characteristics of the S. aureus strains isolated from the blood and heart tissue of included patients to adhere to other human cells (important information regarding the ability to attach to heart tissue; test will be conducted in cell culture)	through study completion (about 1 year)
Secondary	toxine production	characteristics of the S. aureus strains isolated from the blood and heart tissue of included patients regarding production of toxins which will lead to information about induction of inflammation processes and induction of host cell death	through study completion (about 1 year)